X-ray emitter and method for compensating for a focal spot movement

Patent metadata

Field	Value
Publication number	US-10553389-B2
Application number	US-201815912723-A
Country	US
Kind code	B2
Filing date	Mar 6, 2018
Priority date	Mar 9, 2017
Publication date	Feb 4, 2020
Grant date	Feb 4, 2020

Abstract

An X-ray emitter includes an anode rotatably mounted arranged inside a vacuum housing. It can be set into rotation by an electric drive. In the region of a focal spot, the anode can be exposed to an electron beam emitted by a cathode. According to an embodiment of the invention, a control unit is configured to activate an electromagnetic deflection unit that deflects the electron beam as a function of at least one operating parameter of the electric drive such that a movement of the focal spot, caused by electromagnetic fields of the electric drive, can be at least partly compensated for. An embodiment of the invention further relates to a method for compensating for a focal spot movement when X-ray emitters in operation.

First claim

What is claimed is:

1. An X-ray emitter, comprising:
a vacuum housing;
a cathode, arranged inside the vacuum housing;
an anode, arranged inside the vacuum housing, at least the anode being rotatable, the anode being configured to be set into rotation by an electric drive and being exposable, in a region of a focal spot, to an electron beam emitted by a cathode; and
an electromagnetic deflection unit, activatable by a controller, to deflect the electron beam as a function of at least one operating parameter of the electric drive, to at least partially compensate for a movement of the focal spot caused by electromagnetic fields of the electric drive.

2. The X-ray emitter of claim 1 , wherein the anode is designed as a rotating anode, rotatably mounted inside the vacuum housing.

3. The X-ray emitter of claim 2 , wherein the vacuum housing is rotatably mounted and is configured to be set into rotation by the electric drive, wherein the cathode and the anode are non-rotatably connected to the vacuum housing.

4. The X-ray emitter of claim 2 , wherein the at least one operating parameter of the electric drive includes at least one of a stator current amplitude and a stator current phase position.

5. The X-ray emitter of claim 2 , wherein the controller is configured to activate the electromagnetic deflection unit as a function of at least one operating parameter of the X-ray emitter.

6. The X-ray emitter of claim 5 , wherein the at least one operating parameter of the X-ray emitter is at least one of a tube voltage and a temperature.

7. The X-ray emitter of claim 1 , wherein the vacuum housing is rotatably mounted and is configured to be set into rotation by the electric drive, wherein the cathode and the anode are non-rotatably connected to the vacuum housing.

8. The X-ray emitter of claim 7 , wherein the at least one operating parameter of the electric drive includes at least one of a stator current amplitude and a stator current phase position.

9. The X-ray emitter of claim 7 , wherein the controller is configured to activate the electromagnetic deflection unit as a function of at least one operating parameter of the X-ray emitter.

10. The X-ray emitter of claim 9 , wherein the at least one operating parameter of the X-ray emitter is at least one of a tube voltage and a temperature.

11. The X-ray emitter of claim 1 , wherein the at least one operating parameter of the electric drive includes at least one of a stator current amplitude and a stator current phase position.

12. The X-ray emitter of claim 11 , further comprising:
a measuring unit, to determine the at least one operating parameter of the electric drive.

13. The X-ray emitter of claim 1 , further comprising:
a measuring unit, to determine the at least one operating parameter of the electric drive.

14. The X-ray emitter of claim 1 , wherein the controller is configured to activate the electromagnetic deflection unit as a function of at least one operating parameter of the X-ray emitter.

15. The X-ray emitter of claim 14 , wherein the at least one operating parameter of the X-ray emitter is at least one of a tube voltage and a temperature.

16. The X-ray emitter of claim 14 , further comprising:
a further measuring unit, to determine the at least one operating parameter of the X-ray emitter.

17. The X-ray emitter of claim 1 , wherein the vacuum housing is configured to be stationary.

18. A method for compensating for a focal spot movement during operation of an X-ray emitter, the X-ray emitter including an anode, arranged inside a vacuum housing, the anode being exposable to an electron beam to generate X-ray radiation, at least the anode being configured to be set into rotation by an electric drive, the method comprising:
activating a deflection unit, to deflect the electron beam as a function of at least one operating parameter of the electric drive, to at least partially compensate for a movement of a focal spot caused by electromagnetic fields of the electric drive.

19. The method of claim 18 , wherein control of the deflection unit is implemented as a function of the at least one operating parameter of the electric drive in a context of a feed-forward control in a controller, with an actual position of the focal spot being determined as a control variable.

20. The method of claim 19 , wherein the controller performs the activating of a deflection unit as a function of at least one operating parameter of the X-ray emitter.

21. The method of claim 19 , wherein a dependence, of the movement of the focal spot on at least one of the at least one operating parameter of an electric drive and the at least one operating parameter of the X-ray emitter, is stored in a storage medium assigned to the controller as a discrete data structure.

22. The method of claim 21 , wherein the discrete data structure, to generate control signals for the deflection unit, is interpolated.

23. The method of claim 19 , wherein a dependence, of the movement of the focal spot on at least one of the at least one operating parameter of an electric drive and the at least one operating parameter of the X-ray emitter, is stored in a storage medium assigned to the controller as a discrete data structure, as a multidimensional look-up table.

24. The method of claim 18 , wherein a controller performs the activating of the deflection unit as a function of at least one operating parameter of the X-ray emitter.

25. The method of claim 18 , wherein a dependence, of the movement of the focal spot on the at least one operating parameter of the electric drive, is stored in a storage medium assigned to a controller as a discrete data structure.

26. The method of claim 25 , wherein the discrete data structure, to generate control signals for the deflection unit, is interpolated.

27. The method of claim 18 , wherein a dependence, of the movement of the focal spot on the at least one operating parameter of the electric drive, is stored in a storage medium assigned to a controller as a discrete data structure, as a multidimensional look-up table.

Assignees

• Siemens Healthcare Gmbh

Inventors

• Holch Florian
• Taubenreuther Kai-Uwe
• Weidinger Thomas

Classifications

• H01J2235/10

  Drive means for anode (target) substrate · CPC title

• H05G1/52

  Target size or shape; Direction of electron beam, e.g. in tubes with one anode and more than one cathode · CPC title

• H01J35/10

  Rotary anodes; Arrangements for rotating anodes; Cooling rotary anodes · CPC title

• H05G1/30

  Controlling · CPC title

• H01J35/305 Primary

  by using a rotating X-ray tube in conjunction therewith · CPC title